Lighting devices that include a conversion material may conveniently allow the conversion of a source light emitted from a light source into light of a different wavelength range. Often, such a conversion may be performed by using a luminescent, fluorescent, or phosphorescent material. The wavelength conversion materials may sometimes be included in the bulk of another material, applied to a lens or optic, or otherwise located in line with the light emitted from light source. In some instances the conversion material may be applied to the light source itself. A number of disclosed inventions exist that describe lighting devices that utilize a conversion material applied to an LED to convert light with a source wavelength range into light with a converted wavelength range.
However, LEDs and other lighting elements may generate heat during operation. Applying a conversion material directly upon a lighting element (or light source) may cause the coating to be exposed to an excessive amount of heat, resulting in decreased operational efficiency of the conversion material, and possible breakdown of the material.
Current remote color conversion technologies may place the color conversion materials in relatively close proximity to the LED light sources. The conversion materials may be in intimate physical contact with the LED or may be included in the optical system. However, physical integration of the conversion material and the light source may prohibit the ability to adjust the composition of the emitted light, except through the use of filters that may inefficiently absorb the emitted light.
In the past, proposed solutions have attempted to isolate the conversion material from the heat generated by the lighting element by locating the conversion coating on an enclosure. After light is emitted from the lighting element, it may then pass through the conversion coated enclosure prior to illuminating a space. However, coating the entire surface of the enclosure may require copious amounts of conversion coating materials, increasing the production cost of a lighting device employing this method.
Alternatively, previously proposed solutions have disclosed applying a conversion material to a lens, through which the light emitted from a light source may pass. Less conversion material may be required to coat the surface area of the lens, as opposed to the interior of an enclosure. However, the lens may need to be large to allow light to pass with a sufficiently wide projection angle, thereby requiring a large surface area. Although applying a conversion coating to a lens may be an improvement over applying the coating to an entire enclosure, the lens-based proposed solution is still not optimal.
There exists a need for a remote light wavelength conversion device that allows for source light emitted in one wavelength range to be transmitted to a remote location, and convert the source light into a converted light within a converted wavelength range at or before the remote location to illuminate a space. There further exists a need for a remote light wavelength conversion device that performs the wavelength conversion operation away from a heat generating light source with a minimal conversion area.